Hint mode not working on Vimac preferences

[tecnoloco]

Activating hint mode does not show any hints on the Vimac preferences, it appears to crash.

[phrohdoh]

For me on 0.3.17 it does not crash, but still no hints are shown.

[dexterleng]

From my testing, using the Accessibility API on the Vimac itself causes the app to crash, so I just added a guard to prevent this from happening. It can be confusing though - I think I'll add a notification prompt to alert the user that it doesn't work on Vimac itself.